1. Field of the Invention
The invention concerns a method for cooling a transverse flow synchronous machine, in particular a transverse flow machine; in addition, a transverse flow synchronous machine.
2. Description of the Related Art
Synchronous machines with transverse flow are disclosed, for example, in the following publications:    (1) DE 3,536,538 A1    (2) DE 3,705,089 C1    (3) DE 3,904,516 C1    (4) DE 4,125,779 C1
These essentially describe the basic principle and the construction.
These machines comprise at least one stator with at least one armature winding and a rotor lying opposite the armature winding. The rotor is comprised of at least two annular elements arranged next to one another, separated by an intermediate layer of magnetically and electrically nonconductive material, and in the circumferential direction these elements have a plurality of alternatively arranged polarized magnets and soft-iron elements. Such an arrangement of two annular elements forms a pole structure. Transverse flow machines are preferably constructed symmetrically. These then comprise two pole structures separated by a central support disk.
In such a machine, heat is generated during operation both in the rotor as well as in the stator due to the power dissipation occurring through the windings and the magnetic core and caused by induced eddy currents. If suitable measures are not taken, this limits the loadability and thus also the availability or operating time of the A.C. machine. Situations are particularly critical, in which such a machine operates under high load and particularly at high rpm.
In order to avoid this disadvantageous effect, it is basically known to connect the stator to cooling devices. In this way, the heating of the machine and its components can be reduced.
A plurality of possibilities for improving the cooling effect are known from DE 4,335,848 A1 for designing a cooling arrangement in detail in such a way that it has at least one cooling channel, which is incorporated in the stator in the region or in the vicinity of the support disk and a cooling fluid is passed through it. Each cooling channel is separated from the support disk only by a channel cover of minimal thickness and the air gap between rotor and stator. A design with at least [one] axially running cooling channel in a spacer disk, which is provided between a pair of stator segments, is also is known from this publication. The spacer disk lies radially opposite the support disk, is arranged symmetrically relative to the support disk and is thermally insulated opposite the stator segments. It is comprised of a material which is magnetically passive and has good heat conductivity.